This Major Research Instrumentation award permits Dr. Jonathan Cohen and four co-investigators to purchase a high-performance computing instrumentation (3,584 cores; 2TB/core; 100TB flash storage) to be used by faculty, postdocs, graduate students and undergraduates within the Princeton Neuroscience Institute (PNI). The instrumentation will allow the analysis of human brain imaging data at a speed and scale not previously possible.
The collaborating researchers are cognitive neuroscientists and computer scientists at Princeton with complementary expertise in human brain imaging and large scale computing. Two primary research objectives are proposed, building on recent progress in applying multivariate pattern analysis (MVPA) methods from machine learning to detect neural signals that correspond to internal mental states, such as perceptions, memories and intentions that are otherwise not accessible to direct observation. To date, use of MVPA has been restricted to the "offline" analyses" after data have been fully collected. However, a growing and powerful use of brain imaging is to give participants feedback about their brain states in real time, allowing them to use this information to better control brain function (e.g., providing feedback about pain areas as a way of learning to control chronic pain). Such real-time feedback methods could be greatly enhanced by adding MVPA. However, this has been computationally intractable until now. Objective 1 addresses this challenge, by inserting a high performance computing system into the brain scanning pipeline. This will be tested in an experiment that uses MVPA to detect patterns of brain activity associated with sustained attention, allowing us to provide real-time brain-based feedback to improve attentional abilities (with potential educational and health benefits).
Objective 2 focuses on another major advance in brain imaging, in which correlations between areas of activity are analyzed, rather than areas of activity in isolation of one another. Such correlations - often referred to as "functional connectivity" - are likely to reveal more about how the brain actually functions, by providing critical information about the interactions between areas. At present, virtually all approaches to functional connectivity focus on the correlations among a limited set of brain areas of interest. However, a more powerful approach would be to examine the correlation of every area with all others. This requires computing the whole-brain correlation matrix. The analysis of such high dimensional data would be further enhanced by applying MVPA to patterns of correlation. However, doing this further increases computational demands. Applying this approach to a routine brain imaging dataset, using currently available instrumentation, would take 880 years to complete. The work under Objective 2 addresses this challenge, by coupling massively parallel computing with sophisticated software optimizations. Doing so can bring previously intractable problems into the range of practicality. These methods will be tested in an experiment that seeks to identify neural representations of intentions, and their influence on brain mechanisms responsible for executing these intentions.
